U.S. Pat. No. 4,982,039 (Benson) discloses the pyrolysis of halogen-containing organic compounds in a reducing atmosphere at a temperature in the range of about 825.degree. C.-1124.degree. C. The reference discloses the creation of this temperature and reducing atmosphere by combustion of oxygen with a stoichiometric excess of CH.sub.4 or H.sub.2 in accordance with the equations CH.sub.4 +2O.sub.2 .fwdarw.CO.sub.2 +2H.sub.2 O and 2H.sub.2 +O2.fwdarw.H.sub.2 O, respectively. The high temperature cleaves the halogen-carbon bonds of the halogen-containing organic compound and the halogens react with the excess hydrogen (from the excess CH.sub.4 or hydrogen feed) to form HCl. The reaction product stream also contains hydrogen, hydrocarbons, with smaller amounts of carbon, referred to in Example 1 as soot. Unfortunately, the acid formed by this process is contaminated by the water formed from the reaction(s) described above, which leads to the stripping of the acid from the product stream with water, alkali, lime, or generally basic wash. Anhydrous acid has much eater value from the standpoint of her chemical use than acid which contains water.
The result of small amounts of carbon is the same result sought in other pyrolysis processes, e.g., U.S. Pat. Nos. 4,714,796 and 4,851,600.